Refrigerating machine



Oct. 19; 1937.

H. GCLDN ER ET AL REFRl 'GERATING MACHINE Filed Dec. 16, 1956 2 Sheets-Sheet l a m 1. 2 o

la w WW 4.

'Oct. 19, 1937; H. GOLDNER -r AL 2,096,297

REFRIGERATING MACHINE Filed Dec. 16, 1936 2 Sheets-Sheet 2 Patented Oct. 19, 1937 REFRIGERATING MACHINE Hans Giildner and Wilhelm Bock, Stuttgart, Germany Application December 16, 1936, Serial No. 116,225 In Germany December 20, 1935 6 Claims.

This invention relates to a compression refrigerating machine, driven by an electric motor, for pantry refrigerators, which is characterized by, the provision of a pot-shaped evaporator, projecting into the cooling chamber, with a closure cover at. the top, upon which is mounted the driving motor, together with the condenser or liquefier arranged around it, and on the under side of which are suspended the compressor and the regulator 10 of the refrigerating medium within the evaporator, an extension of the motor shaft, for the purpose of driving the compressor, passing through the evaporator pot cover in a gas-tight manner.

There is hereby obtained a structure which is 15 cheap and simple to manufacture and which occuD es very little space. The pot-shaped evaporator may be produced seamlessly in a simple manner by drawing from sheet metal, and requires for the connection of tubes or the like no sort of diswelding. It cannot therefore become leaky, and the gaseous or liquid refrigerating agent contained therein, for instance sulphurous acid, cannot therefore escape into the cooling chamber, 25 thereby endangering food or the like that is to be cooled, The motor and condenser mounted upon the cover of the evaporator are readily accessible for repairs or the like, and the motor also for any changing of its windings for the pur- 30 pose of enabling the machine to be used for a different kind of current or for a different voltage. Owing to the fact that the compressorand the regulator for the refrigerating agent are suspended from the evaporator cover inside the evapo- 35 rator, there is the possibility, in addition to the simple and compact assemblage of these members, of rendering the members suspended from the cover quickly and conveniently accessible for repairs and the like by removing the said cover.

'4 The mounting of the compressor in the evaporator yields a particularly noiseless working of the compressor. The motor arranged outside the evaporator is not exposed to any injury from the gases of the refrigerating agent.

45 The compressor is preferably in a layer of lubri- I continuity requiring to be sealed by soldering or machine becoming materially greater, a ribbed cooling ring.

Furthermore the bottom of the pot-shaped evaporator may be drawn inwards, and in the recess thus formed a freezing pan may be lodged.

The possibility is thus provided, in a simple manner and without taking up additional room, of

. making ice when required.

Fig. 2 is a horizontal section on the line 2--2 in Fig. 3 shows in central sectional elevation a pantry cooling cupboard adapted for the reception of the refrigerating machine, with the refrigerating machine itself shown in elevation;

Fig. 4 shows the refrigerating machine of Fig.

3 on a larger scale, partly. in outside elevation and partly in central section; and

Fig. 5 shows a cross section on the line 3-3 in Fig. 4. v

In Figures 1 and 2, l denotes the pot-shaped evaporator, closed at the top by a lid or cover 2.

The cover is secured by means of screws 35 to an annular flange 4, forming the upper end of the evaporator pot. This flange 4 bears upon the cover I of the cooling chamber by means of an India rubber ring 5. The evaporator thus projects through an aperture 36 in the cooling chamber cover into the cooling chamber itself, and is sealed from the atmosphere by the India rubber ring 5. Above, upon the cover, is mounted loose an electric motor l6 for driving the compressor, with a magnet casing 23, the evaporator cover forming at the same time'the lower bearing plate of the motor. Around the motor is arranged the 40 condenser l5. On the under side of the cover 8 and inside the evaporator are suspended the compressor 2 and the regulator 3 for the refrigerating agent, the former owing to the fact that its casing is made in one piece with the cover, and the latter by means of its supply pipe I8. The compressor and the refrigerating agent regulator are located in a layer of oil 34 provided above the surface 33 of the liquid refrigerating agent accumulating in the evaporator. An extension 29 of .50 the motor shaft passes through the cover 8 by means of a packing 25 for the purpose of driving the compressor.

The armaturelfiof the motor is carried by a sleeve 31, which is mounted upon a step 38 on the pipe I8, which are to be secured to the cover 8.

The cover 8 is preferably so shaped that the pipes I1 and I8 can pass through it outside the magnet casing 23. At its lower and upper ends the magnet casing is provided with holes 24. For repairing work. or the like, the hood 2|, the nut 39 and the wind vane 22, the magnet 23 and the armature l6 can be conveniently removed from the cover 8. Similarly by unscrewing the evaporator cover 8, the machine parts suspended from the under side of the latter can be quickly and conveniently made accessible. The entire machine can be quickly and conveniently suspended in the pantry or cooling chamber or removed therefrom.

The regulator 3 for the refrigerating medium encloses in the usual manner a float with'a needle valve secured thereto below, which co-operates with a discharge pipe 32 connected with the regulator and extending down to about the bottom 9 of the evaporator. A crank pin 4| provided at the lower end of the shaft 29 drives the compressor piston 44 through the medium of a connecting rod 42 and a pivot bolt43, and is supported by means of a footstep bearing, which consists of a ball 28, which rests upon a spring 21, which in its turn rests in a cup-shaped extension 26 of the compressor casing 2. All the movable parts of the compressor, even the suitably constructed bearing of the driving shaft 29 in the cover 8, undergo ample lubrication by the oil surrounding them. To an inner annular groove 38 in the compressor cylinder is connected a suction plpe 3| opening freely near the cover 8, and to the floor i9 of the compressor casing, equipped with a non-return valve 29, is connected 9. pres- 'sure pipe l1.

The refrigerating machine as so far described works in the following manner:

Through the pipe 3| the compressor draws in gaseous refrigerating medium by suction when the motor is working and forces it through the pipe into the condenser l5. In the latter the compressed gas, with the co-operation of the cooling which the condenser undergoes owing to the fact that the wind vane 22 sucks air through the hood 2l'in the direction of the arrows,-is liquefied, while at the same time, through the holes 24 in the motor casing, air is sucked for the purpose of cooling the motor. The regulator 3 for the refrigerating medium allows a quantity of the liquid refrigerating medium flowing to it through the pipe l8 to flow away through the pipe 32, this quantity corresponding to the quantity of gas sucked in through the pipe 3|. The

liquid refrigerating amedium accumulating in the evaporator now evaporates, and in'so doing withdrawsheat from the wall of the evaporator, thereby cooling the air' surrounding the latter. The bubbles of gas ascend through the layer of lubricating oil 34, into the gas chamber located above the latter, out of which they are icontinually sucked away again through the pipe 3| in the manner hereinbefore described. Onto the pot-shaped evaporator is slipped a cooling ring 46, bent out into the ribs 45, for the purpose of reinforcing the cooling action.

The bottom 9 of the evaporator is drawn inwards, and in the recess 49 thus formed is lodged a freezing pan III. This is carried by a dish or cup made of insulating material, which is slipped into the recess from below. By means of radial upper attached ribs 41 of the dish carrier II, the bottom of the freezing pan I0 is located at a distance from the bottom of the pan carrier, and is supported in the latter. Furthermore the pan carrier has on its periphery notches I3, through which the. cold air arising above the freezing pan can pass underneath the bottom of the freezing pan and flow away through the aperture H. For the purpose of holding the pan carrier fast in the recess of the evaporator, there may be soldered to the latteran inwardly projecting pin l2, which can be lodged in a notch 48 in the wall of the freezing pan carrier when the latter is inserted.

The main portions of the machine illustrated in Figures 3 to 5 are the pot-shaped evaporator,

its upper closure cover 8, upon which is mounted the motor 23, and the compressor 2, fitted to the under side of this cover, this compressor dipping into the layer of oil 34. The latter, however, now rests in a. special oil. pan 50, the gas suction space 5| above the layer of oil being placed in communication, by a pipe 52 passing through the bottom of the oil pan in an oil tight manner, with a gas space 53 located below the oil pan and above the surface 33 of the condensed refrigerating medium.

The oil pan 50 is formed at its upper edge with an annular flange 54, by means of which it is lodged in a gas-tight manner between the cover 8 and the flange 4 at the top of the evaporator. The evaporator flange 4 rests by means of the India rubber packing ring 5 upon the top wall I of the cooling chamber 55 of the cooling cupboard 62, in such a way that the evaporator projects into the cooling chamber through an apera ture 36 in the said wall. By means of a coupling 56 the shaft 29 of the motor is secured to a shaft extension 51 serving for driving the compressor.

.with a suction aperture opening into the gas space 5|. Furthermore there is connected to it a pressure or delivery pipe H, which leads to the condenser |5 encircling the motor. The discharge tube 8. of the condenser leads to the refrigerating medium regulator 3 suspended from the cover 8 in the gasspace 53. At the top of the motor shaft 29 is mounted a fan 22. There is slid up from below on to the evaporator, for the purpose of enhancing the cooling action, a sheet metal ring 46, which carries convexities projecting outwards like ribs. The bottom 9 of the evaporator is drawn inwards, in such a way as to produce a cavity 49, into which can be frictionally inserted a metal freezing it, when is provided underneath with a bottom cove g 58 of insulating material. The motor 23, and with it the condenser I5 and the fan 22, are enclosed by a sheet metal hood 59, mounted upon the top wall I of the cooling chamber. This hood has a removable cover 60, and lateralair inlet and outlet apertures 6|. I

The action of therefrigerating machine illustrated in Figures 3 to 5 is fundamentally the same as that of the machine shown in Figures 1 and 2, only a better cooling effect is obtained. This is primarily because the gas evolved by thelayer of aoeaac'r refrigerating medium 33 in the space 53 now passes through the tube 52 directly into the gas suction space that is to say, it no longer has to bubble through the oil layer 34. The gas therefore takes up to a far smaller extent the heat absorbed by the layer of oil 34 from the compressor. The gas in the gas space 5| is therefore cooler than the gas that accumulates above the-layer of oil 34 in the embodiment shown in Figures 1 and 2, and can there transmit its heat directly to the evaporator pot l, diminishing the cooling action of the latter. This direct transmission of heatfand likewise the direct transmission of heat from the oil layer 34 to the 1 evaporator pot, is now prevented by arranging the layer of oil 34 in the special oil pan 50.

The small quantities of oil which are carried of the compressor and its driving members is always ensured.

What we claim is:

1. A compression refrigerating machine for pantry refrigerators, comprising. a pot-shaped evaporator projecting into a chamber to be cooled, a cover closing the top of the evaporator, an electric driving motor mounted upon the said cover,

a condenser, encircling the motor, a compressor suspended in the evaporator from the under side of the cover, the shaft of the motor extending i electric driving motor mounted upon the said cover, a condenser encircling the motor, a layer of lubricating oil above the surface of the liquefied refrigerating medium in the evaporator, a compressor suspended in the evaporator from the under side of the cover and immersed in the said lubricating oil, the shaft of the motor extending downwards through the evaporator cover in a gas-tight manner to drive the compressor, and a regulator for the refrigerating medium, likew se suspended in the evaporator from the under side of the cover. g

3. A compression refrigerating machine for pantry refrigerators, comprising a pot-shaped evaporator projecting into achamber to be cooled, a cover closing the top of the evaporator, an electric driving motor mounted upon the said cover,a condenser encircling the motor, a compressor suspended in the evaporator from the under side of the cover, the shaft of the motor extending downwards through the evaporator cover in a gas-tight manner to drive the compressor, a regulator for the refrigerating medium, likewise suspended in the evaporator from the under side of the cover, a ribbed cooling ring surrounding the evaporator.

4. A compression refrigerating machine for pantry refrigerators, comprising a pot-shaped evaporator projecting into a chamber to be cooled, a cover closing the top of the evaporator, an electric driving motor mounted upon the said cover, a condenser encircling the motor, a compressor suspended in the evaporator from the under side ofthe cover, the shaft of the motor extending downwards through the evaporator cover in a gas-tight manner to drive the compressor, a regulator for the refrigerating medium, likewise suspended in the evaporator from the under side of the cover, the bottom of the evaporator being drawn inwards to form a recess, and a freezing pan lodged in the said recess.

5. A compression refrigerating machine for pantry refrigerators, comprising a pot-shaped evaporator projecting into a chamber to be cooled, a cover closing the top of the evaporator, an electric driving motor mounted upon the said cover, a condenser encircling the motor, an oil pan containing a layer of lubricating oil provided inside the evaporator and above the surface of the liquefled refrigerating medium in the evaporator, leaving intercommunioating gas spaces above and below the said oil pan, a compressor suspended in the evaporator from the under side of the cover and immersed in the said lubricating oil, the shaft 1 of the motor extending downwards through the evaporator cover in a gas-tight manner to drive the compressor, and a regulator for the refrigerating medium, likewise suspended in the evaporator from the under side of the cover.

6. A compression refrigerating machine for pantry refrigerators, comprising a pot-shaped evaporator projecting into a chamber to be cooled, a cover closing the top of the evaporator, an electric driving motor mounted upon the said cover, a condenser encircling the motor, an oil pan containing a layer of lubricating oil provided inside the evaporator and above the surface of the liquefled refrigerating medium in the evaporator, a flange round the upper margin of the oil 'pan, this flange being lodged in a gas-tight manner between the upper edge of the evaporator and the edge of its cover, a tube passing in a. fluidtight manner through the bottom of the oil pan to establish communication between a gas space above the surface of the oil and a gas space be.- tween the bottom of the oil pan and the surface of the liquefied refrigerating medium in the evaporator, a compressor suspended in the evaporator from the under side of the cover and immersed in the said lubricating oil, the shaft of the motor extending downwards through the evaporator cover in a gas-tight manner to drive the compressor, and a regulator for the refrigerating HANS GLDNER. WILHEIM BOCK. 

